The invention relates generally to catheters utilized in interventional medical procedures, and more particularly to a feedback system for a catheter that provides non-visual indications or cues to an individual utilizing the catheter.
Catheters are used in an increasing number of interventional medical procedures to evaluate various conditions of the patient with which the catheter is utilized. In performing the procedure with a catheter, with most catheter designs the physician holds a handle for the catheter from which extends a shaft that is inserted into the body of the patient. The physician holds the catheter handle with one hand while operating controls on the handle with the other hand to move the shaft and catheter tip into the desired location to obtain information on and/or images of the tissue being investigated and/or treated.
Due to the length of the shaft extending from the handle of the catheter, direct tactile feedback from the catheter tip and shaft is limited at the handle and thus the physician through the shaft. This, in turn, limits the ability of the physician to sense the location of the catheter through the tactile feedback from the catheter, i.e., the forces exerted on the catheter tip and shaft by the tissue contacted by the tip and shaft, thereby limiting the information provided to the physician during the procedure. Additionally, other important catheter state information, such as the occurrence of pacing or ablation on that catheter, produce no mechanical feedback to the catheter handle.
In certain prior art solutions to this issue, various imaging/recording systems designed to be connected to the catheter to have been developed that are capable of displaying the information regarding the forces exerted on the catheter tip and shaft on a display in conjunction with the images of the tissue being investigated and/or treated. However, in order to receive this information, the physician must necessarily look at the display in the location where the information is illustrated. This, in turn, requires that the physician look elsewhere than at the images representing the tissue being investigated on the display to view the information. However, these secondary representations on the display can be distracting and are often hard to gauge and require the physician to interpret the information represented, as in a charts, while performing the procedure, all of which can temporarily shift the physician's focus, which is undesirable.
Other alternative solutions to provide the feedback on the forces exerted on the catheter tip and/or shaft include audible sounds and/or warnings, but these provide little, if any information to the physician on the actual forces acting on the catheter tip and/or shaft.
As an alternative to visual and audible feedback systems associated with the recording/mapping/imaging systems to which the catheter is connected, one additional prior art feedback alternative that has been developed is the use of robotic interventional systems that includes haptic feedback provided to the physician. One such system is disclosed in U.S. Pat. No. 8,390,438, entitled Robotic Catheter System Including Haptic Feedback, which is expressly incorporated herein by reference for all purposes. In this system, a robotic catheter system includes an input control system designed to control the operation of a robotic catheter manipulator assembly such that the physician can remotely perform an interventional procedure with the robotic catheter manipulator assembly by utilizing the input control system. The robotic catheter system also includes a haptic feedback system located on the input control system. The haptic feedback system is disposed in conjunction with a user interface device that forms a part of the input control system. The haptic feedback system provides mechanical resistance and other types of feedback to the user through the user interface device corresponding to the resistance and other types of information provided by the catheter and other sources, such as sensors disposed on the catheter.
In addition to the disclosed robotic catheter system, the '438 patent additionally discloses that the haptic feedback system can be disposed directly within a handle for the catheter, in which cases the user input system is omitted. The feedback from the haptic feedback system in this prior art system is sent directly back to the catheter handle to be received by the physician holding the catheter handle in order to provide the information contained within the feedback to the physician.
The '438 patent also discloses an embodiment where the haptic feedback system is configured with the user input system in the form of a glove that is worn by the user and employed with feedback sensors in a three-dimensional imaging system or liquid tank. The sensors on the glove are provided with the feedback from the catheter that is transmitted through the glove to the wearer for use in the performance of the procedure.
While the prior art solution provided in the '438 patent enables haptic feedback to be transmitted directly back to the physician via the user input system, whether a remote system or incorporated into the catheter handle, in either embodiment the utilization of the feedback system requires either the use of a robot and the remote user input system or a catheter handle that is constructed with the haptic feedback system and all of the accompanying feedback devices within the handle. Thus, the haptic feedback system of the '438 patent requires significant increases in equipment investment/cost and complexity in the catheter system utilized to perform the procedure in order to provide the feedback to the physician.
Accordingly, it is desirable to develop a system and method for a haptic feedback system for use with a manually-operated catheter employed in medical interventional procedures that is capable of providing effective haptic feedback to the user of the catheter without significant alterations or changes to existing catheter configurations. It is also desirable that this system allow the use of haptic feedback with wide array of currently available off the shelf catheters so as to allow the physician to choose the most appropriate catheter for the application. Finally, it is desirable that the haptic feedback system allow tactical sensation of more general system events not related to catheter pressure or location (such as the presence of pacing or ablation signals)